• 제목/요약/키워드: 혈액 유동

Search Result 104, Processing Time 0.023 seconds

NUMERICAL ANALYSIS ON THE BLOOD FLOW CHARACTERISTIC IN THE ARTERIOVENOUS GRAFT FOR DIFFERENT INJECTION METHOD OF BLOOD (혈액 투석시 충혈방법에 따른 인조혈관 내 유동 특성에 관한 수치해석 연구)

  • Kim, J.T.;Sung, K.H.;Ryou, H.S.
    • Journal of computational fluids engineering
    • /
    • v.18 no.3
    • /
    • pp.14-19
    • /
    • 2013
  • Renal failure patients have to operate arteriovenous graft for hemodialysis. Blood flow characteristics influence the patency rate of arteriovenous graft. Numerical investigation is performed with the arteriovenous graft according to injection of blood. As a result, when the injection is not applied to venous graft, the low wall shear stress region appears at venous anastomosis. It may cause intimal hyperplasia at venous anastomosis.

3-D Flow Analysis of Blood and Blood Substitutes in a Double Branching Model (이중 분지관내 혈액 및 혈액대용유체의 3차원 유동해석)

  • Suh, Sang-Ho;Yoo, Sang-Sin;Roh, Hyung-Woon
    • Journal of Biomedical Engineering Research
    • /
    • v.18 no.2
    • /
    • pp.187-196
    • /
    • 1997
  • The three-dimensional flow analysis using the finite volume method is presented to compare the steady flow characteristics of blood with those of blood substitutes such as water and aqueous polymer solution in an idealized double branching model. The model is used to simlllate the region of the abdominal aorta near the celiac and superior mesenteric branches. Apparent viscosities of blood and the aqueous Separan solution are represented as a function of shear rate by the Carreau model, Water and aqueoiu Separan AP-273 500wppm solution are frequently used as blood substitutes in vitro experiments. Water is a typical Newtonian fluid and blood and Separan solution are non-Newtonian fluids. Flow phenomena such as velocity distribution, pressure variation and wall shear stress distribution of water, blood and polymer solution are quite different due to differences of the rheological characteristics of fluids. Flow phenomena of polymer solution are qualitatively similar to those of blood but the phenomena of water are quite different from those of blood and polymer solution. It is recommended that a lion-Newtonian fluid which exhibits very similar rheological behavior to blood be used in vitro experiments. A non-Newtonian fluid whose rheological characteristics are very similar to those of blood should be used to obtain the meaninylll hemodynamic data for blood flow in vitro experiment and by numerical analysis

  • PDF

Effect of Bifurcation Angle on Blood Flow in Flexible Carotid Artery (유연한 경동맥 분지관에서 분지각이 혈액의 유동에 미치는 영향에 관한 연구)

  • Lee, Sang Hoon;Choi, Hyoung Gwon;Yoo, Jung Yul
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.37 no.3
    • /
    • pp.229-235
    • /
    • 2013
  • To investigate the effect of the flexible artery wall on the blood flow, three-dimensional numerical simulations were carried out for analyzing the time-dependent incompressible flows of Newtonian fluids constrained by a flexible wall. The Navier-Stokes equations for fluid flow were solved using the P2P1 Galerkin finite element method, and mesh movement was achieved using an arbitrary Lagrangian-Eulerian formulation. The Newmark method was employed for solving the dynamic equilibrium equations for the deformation of a linear elastic solid. To avoid complexity due to the necessity of additional mechanical constraints, we used a combined formulation that includes both the fluid and structure equations of motion to produce a single coupled variational equation. The results showed that the flexibility of the carotid wall significantly affects flow phenomena during the pulse cycle. The flow field was also found to be strongly influenced by the bifurcation angle.

A Numerical Analysis on the Hemodynamic Characteristics in Elastic Blood Vessel with Stenosis (협착이 있는 탄성혈관을 흐르는 혈액의 유동특성에 관한 수치해석적 연구)

  • 정삼두;김창녕
    • Journal of Biomedical Engineering Research
    • /
    • v.23 no.4
    • /
    • pp.281-286
    • /
    • 2002
  • In this study, blood flow in a carotid artery supplying blood to the human's brain has been numerically simulated to find out how the blood flow affects the genesis and the growth of atherosclerosis and arterial thrombosis. Velocity Profiles and hemodynamic parameters have been investigated for the carotid arteries with three different stenoses under physiological flow condition. Blood has been treated as Newtonian and non-Newtonian fluid. To model the shear thinning properties of blood for non-Newtonian fluid, the Carreau-Yasuda model has been employed. The result shows that the wall shear stress(WSS) increases with the development of stenosis and that the wall shear stress in Newtonian fluid is highly evaluated compared with that in non-Newtonian Fluid. Oscillatory shear index has been employed to identify the time-averaged reattachment point and this point is located farther from the stenosis for Newtonian fluid than for non-Newtonian fluid The wall shear stress gradient(WSSG) along the wall has been estimated to be very high around the stenosis region when stenosis is developed much and the WSSG peak value of Newtonian fluid is higher than that of non-Newtonian fluid.

생체유체역학과 유체공학

  • Seo, Sang-Ho;No, Hyeong-Un
    • Journal of the KSME
    • /
    • v.50 no.8
    • /
    • pp.32-35
    • /
    • 2010
  • 생체유체역학은 혈관질환을 일으키는 혈액유동에 관한 학문으로 유체역학에 그 바탕을 두고 있다. 이에 따라 이 글에서는 생체유체역학과 유체공학의 관계를 설명하고, 생체유체역학의 분야를 설명함으로써 향후 국내 생체유체역학 연구에 있어 기계관련 공학자로서 앞으로 나아가야 할 일들을 정의하고자 하였다.

  • PDF